<!DOCTYPE html>
<html>
<head>
    <meta charset='utf-8'>
    <meta http-equiv='X-UA-Compatible' content='IE=edge'>
    <title>Page Title</title>
    <meta name='viewport' content='width=device-width, initial-scale=1'>
    <link rel="stylesheet" href="./bootstrap-3.4.1-dist/css/bootstrap.min.css"/>
    <link rel="stylesheet" href="./bootstrap-3.4.1-dist/css/bootstrap-theme.min.css"/>

</head>
<body>



<div class="<div class="container-fluid">
    <form action="#">
        <div class="form-group">
            <label for="name" class="col-sm-2">邮箱</label>
            <div  class="col-sm-10">
                <div class="input-group">
                        <input type="text" class="form-control" id="mail"/><span class="input-group-addon">@</span>
                    </div>
            </div>
        </div>
        <div class="form-group">
                <label for="name" class="col-sm-2">邮箱</label>
                <div  class="col-sm-10">
                    <div class="input-group">
                            <input type="text" class="form-control" id="mail"/><span class="input-group-addon">@</span>
                        </div>
                </div>
            </div>
    </form>

</div>
<script type="text/javascript" src="./bootstrap-3.4.1-dist/js/bootstrap.min.js"></script>
</body>
</html>